Motor Oil: We hear the message all the time: "Change your oil." So why is this important? Well, motor oil is perhaps the single-most critical fluid in your vehicle. Motor oil is the key lubricant that allows all those moving metal parts inside your vehicle's engine to spin freely. It protects these moving parts, helps cool the engine, suspends contaminants so they can be removed in the oil filter, and more. Plus, modern motor oil can even provide a small but measurable fuel economy benefit compared to motor oils of yore.
Motor oil is created by blending a "base oil" usually refined from petroleum with a chemical additives package that helps the motor oil perform a wide variety of tasks over a broad range of temperatures. (Many years ago, drivers had to use both a "summer" motor oil in hot temperatures and a "winter" motor oil in cold temps.)
The interval at which motor oil should be changed varies by car manufacturer, but the simple fact is that motor oil inside any car that has an internal combustion engine (even hybrid vehicles) eventually sees its additive package become depleted, which necessitates its replacement.
The above was written by Garreett McKinnon and was published in the Fall 2011 edition of Vehicle MD